Rock drill



Sept. 7 Q1926.

- 1599,19? W. J. BARNETT ROCK DRILL Filed Nov. 3, 1925 I INVENTOR- WILL AM J BARNETT BY I Patented Sept. 7, 1926.

UNITED STATES OF NEW JERSEY. I

Application filed November v This invention relates to rock drills of the hammer type and like percussive tools.

In drills of the type referred to and like water tube fixed axially inthe machine hav- I ing its forward end extending into the shank of the hollow steel and its rear end communicating with the water line. .According to this arrangement care must be taken to see that the hole in the shank is sufiiciently large in order to permit the water tube to enter the shank freely, otherwise damage to the tube will result. a

The construction briefly outlined in the last preceding paragraph and other known constructions are defective in th-at (a) Air is always present in the chuck cavity under more or less pressure and finds its way through the steel to the cutting face.

(6) Water pressure at the cutting face of hit is considerably less than water line pres sure owing to leakage into the chuck.

The object of the present invention is to provide a rock. drill of the type referred to or like percussive tool which shall be free of the defects above set out.

In accordance with my invention I provide a rock drill of-the hammer type or like percussive tool having a water tube so arranged and combined that it is free or floating in the sensethat it is not positively joined or rigidly fixed or secured so as to prevent longitudinal movement.

The forward end of the floating tube passes over or within the bore of the shank of the steel or the bore of the anvil block as the case may be and under all operative conditions is maintained so closely associated with the bore of the shank (or anvil block) by reason of pressure imparted at the rear end thereof, as to make and always maintain an airtight joint thereby preventing the escape of water from the tube into the chuck cavity and preventing also the entry of air from the chuck cavity into the shank.

In order that my invention may be readily understood and carried into practice ref- AT Orrigg;

WILLIAM JAMES BARN EDT, 01? KENILVJOR'IH, TBAI SVAAL'SOUTH AFRICA, ASSIGNOR TO INGERSOLL-RAND COMPANY, 6F JERSEY CITY, NEVI JERSEY, A CORPORATION ROCK DRILL.

3, 1925. Serial No. 86,491.

erence is hereby made to the accompanying sheetof illustrative drawings, showing a sectional view of an embodiment of my invention and from which it will be seen that in accordance with the example illustrated I provide a free or floating water tube A axially in the-machine and passing through the rifle bar (not shown) through a piston, only the front extension A of which is shown, and into the shank B of the steel C. The forward end of the water tube is tapered at Dandengages a shoulder E in the shank formed by a counter bore or otherwise, and the rear end is furnished with a spring F thus imparting pres sure which causes the forward end of the tube to be maintained in close engagement with the shank of the steel.

The spring F takes the form of a compression spring and is seated within a cylinder G in the handle H, the front end of the spring engaging a washer I loose in the cylinder G and the rearend engaging a plug J. The loose washer I permits water to pass to the water tube from any suitable or usual water connection connected to the cylinder G forwardly of the Washer.

The plug J may be 'so formed as to admit of the adjustment of the compression of the spring.

The washer I passes over the rear end of the tube A and is maintained in position 1y an enlarged surface K being a ball formed near the rear end of the tube.

The forward end of the cylinder Gr carries a stu'fiing box and gland L.

Water delivered to a passage 0 in the handle I-I through a suitable conduit (not shown) passes into a chamber P in the cylinder G,'from 'whence it flows around the ing' free tomove longitudinally and follow both the forward and the backward movements of the drill steel, and a compression.

spring at the rearward end of the Water tube in said handle cylinder exerting pressure against said enlarged tube surface normally tending to force the Water tube forward ly and maintain close contact between the Water tube and the drill steel, whereby air A is prevented from passing down the drill 10 steel. V

Signed at Johannesburg in the Transvaal Province of the Union of South Africa this 2nd day of September A. D. 1925.

WILLIAM JAMES BARN TT; 

